The COVID-19 vaccine candidate Nanocovax was found to be safe and well-tolerated, and it induced robust immune responses up to day 90, according to interim results published in The Lancet Regional Health Western Pacific.
Researchers performed a 2-phase trial to assess the safety and immunogenicity of the Nanocovax vaccine, a novel recombinant COVID-19 subunit vaccine (ClinicalTrials.gov, NCT04683484). The first phase was a dose-escalation, open-label trial, and the second phase was a randomized, doubleblinded, placebo-controlled trial. Patients included in phase 1 (n=60) received 2 intramuscular injections (IMs) of the Nanocovax vaccine. For phase 2 of the trial, patients (n=560) were randomly assigned in a 2:2:2:1 fashion to receive either an IM of Nanocovax at doses of either 25, 50, or 75 mcg, or an aluminum hydroxide adjuvant at a dose of 0.5 mg (placebo). The primary outcomes were reactogenicity and safety in phase 1, and phase 2 outcomes included safety, anti-SARS-CoV-2 (S) immunoglobulin (Ig) G response, and the incidence of solicited and unsolicited adverse events (AEs) after 7 and 28 days, respectively.
There were no severe AEs observed among the 60 patients included in phase 1. In addition, most AEs among this patient cohort were of mild or moderate severity and resolved shortly after receipt of the vaccine.
Among the 560 patients included in phase 2, the rate of any solicited AE was 37.7% and 35.7% after receipt of the first and second vaccine dose, respectively, with local pain as the most commonly reported AE (~32%). Unsolicited AEs were observed among 157 (28%) patients and most were of mild severity, with similar rates noted between those who received the vaccine vs placebo. For most patients, reactogenicity was either absent or mild, with a mean duration of 3 days or less. No severe AEs associated with the Nanocovax vaccine were reported among patients included in phase 2 of the trial.
The vaccine induced robust anti-S IgG and humoral responses among all patient groups, with peak responses observed 42 days after administration. Of note, undetectable type 1 helper T-cell responses were observed among 84 randomly patients.
Study limitations included the lack of diversity among the included patients, the short follow-up period, and the small number of convalescent samples.
The researchers concluded, “[these] data show that Nanocovax is ready for a phase 3 trial for further evaluation on the safety and efficacy in a large population.”
Disclosure: Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Nguyen TP, Do Q, Phan LT, et al. Safety and immunogenicity of Nanocovax, a SARS-CoV-2 recombinant spike protein vaccine: Interim results of a double-blind, randomised controlled phase 1 and 2 trial. Lancet Reg Health West Pac. 2022;24:100474. doi: 10.1016/j.lanwpc.2022.100474.